LSD was accidentally created in 1938 by the Swedish scientist Albert Hofmann as he was experimenting with derivatives of lysergic acid derived from the ergot fungus. No one knew of its psychological effects until Hofmann accidentally dosed himself with LSD in 1943.

LSD was first introduced to the medical field as a treatment for temporary psychotic states in the 50s.  There was much interest in LSD-enhanced therapy.  In the 1950s and 60s, over 1,000 medical papers and over 12 books were published on psychotherapeutic use of LSD (9).

However, by the end of the 1960s, the recreational use of LSD was gaining in popularity. Recreational LSD use was so prominent during the 60s and 70s that the ‘psychedelic movement’, which involved excessive use of LSD, still defines the era. With such an explosion into recreational use and a perceived risk for abuse, LSD possession was declared illegal in 1968. LSD is a schedule I drug meaning that it’s possession, purchase, manufacture, and distribution is illegal and it is illegal to use in medical treatment. LSD is also under similar legal classifications in other countries (10).

Due to the excessive recreational use, and illegality of LSD during the psychedelic movement the therapeutic use of psychedelics by professionals quickly fell out of favor. By the late 80s though, scientific interest was starting to pique again and the Swiss government granted permission for a research group to study potential therapeutic uses of both LSD and MDMA. However, the following government withdrew permission to prescribe both of them over concerns of a lack of proper methodology and the death of a patient following consumption of ibogaine (11, 12).

While interest in LSD as a recreational drug has remained throughout the decades, there has been a recent surge of interest in micro-dosing LSD to enhance cognitive function and creativity without experiencing the strong hallucinatory effects that would occur at higher doses (13).

LSD appears to create neuroplasticity, increased growth and complexity of neurons (14). These effects on the brain may explain LSD’s  therapeutic benefits, in treating a number of mental health conditions including: anxiety, depression, and addiction.

It is critical to carefully consider your mindset, intentions, and safety and comfort of the environment before taking any psychedelic as this will profoundly affect the experience. Also the role of integrating the experience into your everyday life is a critical part of it’s therapeutic ability, and why these substances work well when combined with therapy or community support.

LSD treatments help decrease baseline anxiety levels up to several months after treatment when used in conjunction with psychotherapy.  LSD reduced depressive symptoms in patients with cancer or life-threatening diseases.

• A double-blind, randomized, placebo-controlled study investigated the effects of LSD treatment and psychotherapy on 12 patients with anxiety associated with a life-threatening disease. Patients received two LSD treatments two to three weeks apart in conjunction with psychotherapy. At two months post-treatment, patients had significantly reduced anxiety scores and no adverse side effects beyond the day of LSD treatment. The reduction in anxiety scores was maintained for 12 months (15).
• A review of the treatments given to treat psychiatric conditions in end-stage cancer patients found that even a single dose of LSD was linked to rapid and maintained reductions in anxiety and depressive symptoms (16).
• A systematic review of the safety and efficacy of hallucinogens found that limited doses of drugs such as LSD seemed to be well-tolerated and safe, although long-term studies are needed to fully establish the safety and effects of hallucinogenic treatment (17).
• A double-blind, placebo-controlled trial of 29 patients with cancer-related anxiety and depression were treated with a single dose of psilocybin, the active ingredient in ‘magic mushrooms’. Patients saw rapid and enduring improvements to anxiety and depression, indicating that hallucinogens, in general, may positively affect anxiety levels (18).

Several reviews of LSD and addiction have concluded that LSD may be effective for treating drug dependence to alcohol and tobacco, especially in patients resistant to conventional treatments.

• A review of LSD’s effect on addiction symptoms found that there is evidence that LSD has potential as a treatment for addiction. LSD’s effects on neurotransmitters such as serotonin receptors, as well as its pharmacology and effects on gene expression, show that LSD may be effective as an addiction treatment (19).
  
  
• A meta-analysis of randomized controlled trials investigating the treatment of alcoholism with LSD found that LSD is associated with a reduction in alcohol abuse (20).
  
  
• A systematic review of clinical trials involving hallucinogens found that LSD treatment may be effective for treating tobacco, alcohol, and drug dependence, especially in treatment-resistant patients (21).

Evidence shows that LSD treatment increased optimism, openness, enhanced social behavior, and empathy. While improving general mood and outlook is not strictly a focus of medication, it is still an important improvement to mental health and quality of life that many could benefit from.

• A study of 20 healthy volunteers delivered participants LSD and placebo on two separate occasions, two weeks apart. Patients were then analyzed at baseline and two weeks after each session. The results showed that LSD treatment resulted in heightened mood, increased optimism and increased trait openness two weeks post-treatment, while no positive psychological changes were seen with placebo treatments (22).
• Two placebo-controlled, double-blind, randomized studies investigating the effects of LSD on emotional processing found that LSD induced feelings of happiness, trust, and closeness to others. LSD treatment also enhanced social behavior and implicit emotional empathy as measured by the Multifaceted Empathy Test (23).

While LSD holds a lot of therapeutic promise, it can have serious side effects. It is critical to carefully consider your mindset, intentions, and safety and comfort of the environment before engaging in any activity that will expand your awareness, as this will profoundly affect the experience.

The most likely risk associated with LSD is the “bad trip” (anxiety, fear, paranoia).  Though even in unprepared, and unsupervised conditions violent or self-destructive behavior is very rare,  such events are possible (32). 

LSD can provoke the onset of prolonged psychosis in vulnerable individuals making it critically important to investigate the mental history of family members before taking any psychedelic. 

Another important consideration, is the integration of the experience into your daily life.  While taking LSD, unconscious material may be brought to the surface during the session and if it is not worked through or integrated properly, may lead to negative emotions or experiences after the session  (33).

Reports of complications are extremely rare, especially in supervised and controlled circumstances.

Twenty drugs were ranked, taking into account their individual and societal harm.  LSD was third to last, approximately 1/10th as harmful as alcohol (24). The most significant adverse effect was impairment of mental functioning while intoxicated.

Though LSD is not toxic, a number of  compounds being sold as LSD are.  It is wise to test your “LSD” before consuming it. Though even using a proper test kit does not ensure it’s safe.

Do NOT take LSD If…

• You don’t understand what LSD is and its potential effect
• You’re feeling pressured to take LSD because of others
• You’re taking antidepressants such as SSRIs or antipsychotic medication
• You’re pregnant 
• You do not trust the person who is giving you LSD
• You or your family have a history with schizophrenia, bipolar disorder, or other psychotic disorders
• You have severe clinical depression
• You have or have had suicidal thoughts, attempts or instances of self-harm
• You are not comfortable in your environment
• You don’t know the dose you are taking
• You don’t know for certain what you are taking is LSD (get a test kit)

Side effects of LSD may include (25):

• Paranoia
• Anxiety
• Fear of death
• Distorted perception of objects, depth, and time
• Visual and auditory hallucinations
• Alter body temperature
• Reduce appetite
• Tremors
• Hallucinogen Persisting Perception Disorder (HPPD)
• Damage from foreign substances added to LSD
• Vomiting
• Respiratory problems
• Comatose states (from extremely high doses)

Contraindications

 As LSD is a controlled psychoactive substance, and side effects are possible, it is important to seek medical advice and use caution when using LSD alongside other medications or substances.

Those with the following contraindications should avoid LSD consumption:

• Lithium may greatly increase the effects of LSD
• Some antipsychotic and antidepressant medications may alter the effects of LSD
• Alcohol can negatively alter the effects of LSD
• Pregnant or breastfeeding women
• Cardiovascular disease
• Epilepsy
• Schizophrenia

You can read more about potential adverse drug interactions with LSD here.

Addiction Potential

 LSD is  considered physiologically safe and does not produce dependence or addiction (26).   LSD may even be an effective treatment for substance dependency, such as alcohol and nicotine.  Like any substance, it can be abused in ways that compromise the safety of the individual and others.  Consistent use of LSD may cause difficulty in adjusting back to reality, especially if it is being used as an escape rather than a tool to help improve wellbeing.

Long-Term Effects

 Although scientific research has been limited on LSD due to its prohibition as a Schedule 1 drug, much of the research carried out in the 50s and 60s showed no long-term brain damage.

LSD, and other psychedelics, cause no long-term physical dependency or addiction. Although moderate LSD use temporarily reduces serotonin levels, it does not have a long-term effect. If intermittent abstinence is practiced, serotonin levels will return to normal within a week or two.

One long-term (although rare) effect of psychedelic use is hallucinogen persisting perception disorder (HPPD). HPPD is characterized by a continual presence of sensory disturbances, most often visual, sometimes continuing for months or years following psychedelic use. HPDD is most often, but not always, diagnosed in individuals with a history of previous psychological issues or substance misuse (27), and is seen in patients with high rates of anxiety, obsessive-compulsive disorder, hypochondria, and paranoia.  It is most often associated with LSD (28).

Some older research has found associations between LSD use and increased panic attacks, prolonged psychoses, and post-hallucinogenic perceptual disorders (HPPD) (29). LSD may activate latent mental health problems, in vulnerable individuals (30).  If you have a family history of mental illness (especially schizophrenia), it is advised to avoid any psychedelics.

In one study a single dose of LSD (200 μg) was administered to 16 healthy patients and various factors were measured at one month and 12 months to determine the subjective long-term effects of LSD. The results showed that the single-dose had provided a meaningful experience for users and had long-lasting positive effects (31).

Harm Reduction Measures

• Know why you are taking it
• If it’s your first time, start slow. You can always take more, but you can never take less. Keeping this philosophy in mind, with any substance you consume, will minimize unnecessary harm. 
• Use LSD in a safe and comfortable environment
• Test your LSD.  Many compounds being sold as LSD are toxic.
• Have a sober sitter